#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char * argv [ ])
{
    int *p = NULL;

    p = (int*)malloc(4);
    if (p == NULL)
    {
        perror("malloc failed");
    }
    printf("address [0x%p]\r\n", p);

    free(p);
    free(p);	/* 重复释放*/

    return 0;
}
